I'm the best case to understand significantly-viewed.
I am 22 miles from both DC and Baltimore, but am in what is known as the Baltimore market area, according to Nielsen Media Research.
The cable companies, for this area mainly Comcast, because they generally must broadcast all stations within a 35-mile radius, pick up the Baltimore and the DC channels.
DBS, until 2004, was only allowed one market. With the passage of the SHVERA, significantly-viewed rules were added for DBS. That means DirecTV and Dish Network could add significantly-viewed channels to a local package for a given area, such as a county.
In my county, Anne Arundel, Dish Network did offer Baltimore and the significantly-viewed DC locals. That was, until the court case came to a conclusion with the out-of-market injunction, which cut off the DC locals from this county. DirecTV has never added the DC locals to this county. Which is somewhat strange, because one would think DirecTV would like to compete more favorably with Comcast here.
However, any channel that is significantly-viewed must also have a carriage contract, which I believe is slightly different than the carriage contract which was signed for in-market broadcasts.
I know. Confusing as anything.